Ultra-high resolution imaging for concealed weapon detection at standoff ranges (e.g., 80 to 300 feet) can require high frequencies and a very large aperture to generate an extremely narrow beam to provide very fine resolution (e.g., of the order of one inch or less). Scanning of the beam across the area of interest can take time, which can be difficult when imaging a moving subject. Signal parameters, such as amplitude, time-delay, carrier-frequency, and modulation type are known to affect the performance of simple radar systems and advanced radar based imagery systems using synthetic aperture radar (SAR) techniques. In SAR systems, the motion of the platform hosting the radar transmitter can be used to synthesize a much larger antenna aperture, consequently resulting in a higher resolution in one dimension than is possible with a smaller physical aperture. A similar approach can be applied to a physical aperture by sub dividing it into multiple sub-apertures and transmitting and receiving by each sub-aperture sequentially. The two way returns received by each sub-aperture can then be processed to obtain a resolution that is twice as good as the resolution obtained by the physical aperture. However, this approach can likewise require that the target be motionless, as any movement larger than about 0.01 inches (i.e., a fraction of the wavelength at Terahertz frequencies) during the time it takes for the entire reflector to be sequentially covered by the small sub-apertures can cause defocusing.